Tool dressing device

ABSTRACT

A tool sharpening or dressing device provides a blade having a knife edge held within an aperture from below so that as the tool is drawn along a surface above the edge is able to trim the tool. The blade is clamped by a rotating washer with detent grooves to finely position the washer. The washer, in turn, pushes against the blade to position it.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to tool sharpening or dressing devices,and more particularly to a tool sharpening or dressing means having apositionable cutting blade and a guide for moving a tool relative to theblade so as to remove some material from the tool for dressing thetool's surface.

2. Background

Tool sharpening and dressing devices are well known in the prior art.These devices are used for sharpening knives, drill bits, and many otherproducts that require either a keen edge or a dressed edge. Flexibleplastic film sheet is commonly adhered to window glazing for variousreasons. In the art of applying such film sheet a tool that is commonlyused is a highly flexible doctor blade made of a rubber-like material.Such a doctor blade is pressed against the film sheet and drawn acrossthe sheet to remove wrinkles and air pockets captured under the sheet.As such, such a doctor blade must have a dressed edge that is smooth anduniform. In use, such edges become nicked and cut so as to requirere-dressing and re-sharpening. The present invention is well adapted forsuch, and may be used, as well, for a wide range of other applications.

The prior art teaches blade holders for cutting and dressing many kindsof tools. However, the prior art does not teach that such a blade holdermay be adapted for finely positioning a cutting edge in a manner that issimple and inexpensive to manufacture. The present invention fulfillsthese needs and provides further related advantages as described in thefollowing summary.

SUMMARY OF THE INVENTION

The present invention teaches certain benefits in construction and usewhich give rise to the objectives described below.

A tool sharpening or dressing device provides a blade having a knifeedge held within an aperture from below so that as the tool is drawnalong a surface above the edge is able to trim the tool. The blade isclamped by a rotating washer with detent grooves to finely position thewasher. The washer, in turn, pushes against the blade to position it.

A primary objective of the present invention is to provide such anapparatus having advantages not taught by the prior art.

Another objective is to provide such an apparatus that is veryinexpensive to manufacture.

A further objective is to provide such an apparatus where fineadjustment of the cutting edge is quite simply accomplished.

Other features and advantages of the present invention will becomeapparent from the following more detailed description, taken inconjunction with the accompanying drawings, which illustrate, by way ofexample, the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying drawings illustrate the present invention. In suchdrawings:

FIG. 1 is a perspective view of the preferred embodiment of the presentinvention showing a top side being used to sharpen a tool;

FIG. 2 is a perspective view thereof showing an underside of theinvention;

FIG. 3 is a plan view of the underside thereof; and

FIG. 4 is a sectional view thereof taken along line 4--4 in FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION

The above described drawing figures illustrate the invention, a tooldressing apparatus comprising a rigid body 10 as shown in FIG. 2preferably having a U-shape for improved rigidity. The body provides aplanar surface 20 as shown in FIG. 1, the planar surface having anaperture 30 therein and, a pair of parallel guide surfaces 40A and 40B,the guide surfaces extending away from the planar surface 20 andapproximately at right angles thereto. Preferably, the guide surfacesare functionally a part of respective guide ridges 42 as shown inFIG. 1. A blade support surface 50 is positioned adjacent to theaperture 30, the blade support surface 50 providing a cutting bladeguiding means 60. The guiding means is preferably a pair of spaced apartelongated bumps as shown in FIG. 3. The apparatus further including acutting blade 70 having a cutting edge 80, the blade fitting slidinglybetween the elongated bumps so as to maintain its orientation andattitude. A blade clamping means 90 such as a disk shaped element, ispreferably adapted by its size and shape for rigidly holding the cuttingblade 70 in the aperture 30 for dressing a tool 5 drawn along the rigidbody 10 in contact with the planar surface 20 and also in contact withat least one of the pair of guide surfaces 40A,B. The blade clampingmeans 90 is further preferably adapted for moving the cutting blade 70along the blade support surface 50 in a direction 110 (FIG. 3)corresponding to the cutting blade guiding means 60 to a preferredposition in the aperture 30.

Preferably, the blade support surface 50 is placed at an angle, such as10 to 15 degrees, relative to the planar surface 20 so as to positionthe cutting blade 70 at that same angle for enabling a preferredattitude of the cutting edge 80. Preferably the blade clamping means 90provides a clamping surface 92 and a tensioning means 94 for biasing theclamping surface 92 against the cutting blade 70 for immobilizing thecutting blade against the blade support surface 50. The blade clampingmeans 90 is preferably the screw and tapped hole best shown in FIG. 4.If the material of which the body 10 is fabricated is soft enough, thescrew may have a self tapping screw thread and may be merely installedwithin the body by rotation into a clearance hole. It should be pointedout that in FIG. 3, the blade clamping means 90 is omitted so that theseveral features on the blade support surface 50 may be seen, and sothat several features of the blade clamping means 90 may be pointed out.

Preferably, the blade support surface 50 further provides a detent means52 for adjusting discrete fixed positions of the blade clamping means 90and the cutting blade 70 therewith. How this is accomplished will bedescribed below. Preferably, the detent means 52 provides a plurality ofridges for accepting a first bump 54 which is integral with the clampingsurface 92 of the blade clamping means 90 and shown in its typicalposition against the detent means 52 by a dashed circle in FIG. 3. Thefirst bump 54 is positionable between any two of the ridges forestablishing one of the discrete fixed positions of the clamping means90 as it is rotated about the screw referenced by numeral 94.

Preferably, the blade clamping means 90 further provides a fingerengagable protuberance 96 functional for moving the first bump 54between the ridges as clamping means 90 is rotated about the screw.Preferably a second bump 98 is also formed integrally with the clampingsurface 92 of the blade clamping means 90 and is positioned, as shown inFIG. 3 by the respective dashed circle, so as to contact the cuttingblade 70 for positioning and for immobilizing the blade 70. This may beunderstood in that a force on the blade caused by the passing of thetool 5 will tend to move the blade 70 away from the aperture 30. Secondbump 98 is a stop so that the blade 70 cannot so move.

Preferably, the parallel guide surfaces 40A,B are positioned at an anglerelative to the cutting edge 80 so as to cause the cutting edge 80 toprovide a shearing action against the tool 5 as it passes. Such an angleis advantageously about 80 degrees.

It should be clear that in use, the blade 70 is placed between theelongated bumps of the guide 60 and clamping means 90 is rotated untilsecond bump 98 forces the blade 70 to assume a preferred position withinthe aperture 30. Screw 94 is tightened so as to insure that blade 70 isimmobile. When the cutting edge must be further extended, it isaccomplished by further rotating the clamping means 90 as shown by thearrows in FIG. 2.

While the invention has been described with reference to at least onepreferred embodiment, it is to be clearly understood by those skilled inthe art that the invention is not limited thereto. Rather, the scope ofthe invention is to be interpreted only in conjunction with the appendedclaims.

What is claimed is:
 1. A tool dressing apparatus comprising:a rigid bodyproviding:a) a planar surface, the planar surface having an aperturetherein; b) a pair of parallel guide surfaces, the guide surfacesextending away from the planar surface and approximately at right anglesthereto; and c) a blade support surface adjacent to the aperture, theblade support surface providing a cutting blade guiding means; a cuttingblade having a cutting edge; and a blade clamping and positioning means;the blade clamping and positioning means being adapted for rigidlyholding the cutting blade in the aperture for dressing a tool drawn incontact with the planar surface and at least one of the pair of guidesurfaces; the blade clamping and positioning means being further adaptedfor moving the cutting blade along the cutting blade guiding means to apreferred position in the aperture; the blade clamping and positioningmeans providing a clamping surface and a tensioning means for biasingthe clamping surface against the cutting blade for immobilizing thecutting blade against the blade support surface; the blade supportsurface further providing a detent means for adjusting discrete fixedpositions of the blade clamping and positioning means and the cuttingblade therewith; the detent means providing a plurality of ridges foraccepting a first bump integral with and extending from the clampingsurface of the blade clamping and positioning means, the first bumpadapted by position and size for being positionable between any two ofthe ridges for establishing one of the discrete fixed positions of theblade clamping and positioning means.
 2. The apparatus of claim 1wherein the blade support surface is placed at an angle relative to theplanar surface so as to position the cutting blade at said angle forenabling the preferred position of the cutting blade.
 3. The apparatusof claim 1 wherein the blade clamping means further provides a fingerengagable protuberance functional for moving the bump between the ridgesand for further moving a second bump integral with and extending fromthe clamping surface of the blade clamping and positioning means, saidsecond bump being positioned for pressing against the cutting blade formovement thereof.
 4. The apparatus of claim 1 wherein the parallel guidesurfaces are positioned at an angle relative to the cutting edge.